October 17, 1917 – The Battle of Moon Sound was a naval battle fought between the forces of the German Empire, and the then Russian Republic (and three British submarines) in the Baltic Sea from 16 October 1917 until 3 November 1917[1] during World War I. The German intention was to destroy the Russian forces and occupy the West Estonian Archipelago. The German Navy had 1 battlecruiser, 10 battleships, 9 light cruisers, 1 mine cruiser, 50 destroyers and 6 submarines while the Russians had only 2 pre-dreadnoughts, 3 cruisers, 3 gunboats, 21 destroyers and 3 submarines. It was the German’s intention to destroy the Russian Army and occupy the West Estonian Archipelago (Moonsund Archipelago). The Germans captured the archipelago, with its main islands of Saaremaa (Ösel), Hiiumaa (Dagö), and Muhu (Moon) during the Operation Albion in September 1917. This left a Russian squadron consisting of the old Russo-Japanese War-era pre-dreadnought battleships Tsesarevich, and Slava, together with cruisers and destroyers, stranded in the Gulf of Riga. The Russian fleet escaped on 17 October 1917 by way of the Suur Strait separating the island of Muhu from the Estonian mainland. At the start of the Battle of Moon Sound, there were two submarines in the Gulf of Riga. They were C27 Lt. Sealy and C32 Lt Satow. When the Germans got there, Captain Francis Cromie sent out another submarine called C26 Lt Downie. On the night of the 16th of October, Lt Sealy shot two torpedoes at two German ships but missed at first. They shot two more and made contact. The C27 returned to Hanko when it was not needed. The unit C32 attempted to take out a German ship but was seen and bombed. In the afternoon of 16 October, Gruppe Behncke travelled to the south exit of the Suur Strait and dropped anchor around 8:30 pm. All German ships were anchored in a close line with a torpedo boat at each end. The Germans made significant progress on shore on 16 October. They took 120 officers and 400 men prisoner as well as 49 guns. By the end of the day, German forces were prepared to capture the West Estonian Archipelago and the navy was ready to attack in the Matsalu Bay and the Suur Strait. The Russian battle strategy was changed at 4:30 am on October 17 because of a mistake made in the tranfer of an order. That morning, ships were on the move by 7:00. The 3rd M.S.H.F was heading east while the 8th H.f.F.l. was heading north under command of Erich Koellner. At 7:20, Russian battleships opened fire on the 8th H.f.F.l, the 3rd M.S. Dive and the Sperrbrecher. The 8th advanced but were under constant Russian fire. It was the 3rd M.S.H.F’s duty to clear mines. At 8:00 am Adm. Behncke ordered that the cruisers stay put and not advance any farther. At this point, the SMS König and Kronprinz headed East by the 3rd M.S.H.F, both under the command of Georg von der Marwitz. Slava was advancing so that she came between Paternoster and Werder and started firing upon any east-bound German ship. While this was going on, the 3rd M.S.H.F. had reached Laura Bank and turned north, König and Kronprinz continued east and Slava was now heading north. Adm. Hopman was now heading west towards the Väike Strait. At 9:10, two Russian ships that had returned south opened fire on the 3rd M.S.H.F. The Russians now understood that if they could stop the minesweepers, they could stop the entire German attack. At 9:40, 3rd Ms. Dive was brought over to the east side of Russian minefields to assist the 3rd H.f.F.l By 10:00, the minesweepers were on the northern edge of the rectangular minefield. König and Kronprinz now went forward. Around 10:13, König opened fire on Slava. By 10:17, Kronprinz followed König`s lead and opened fire on Graschdanin. Bayon was also attacked by König. Slava took many underwater hits, causing extensive damage. The battleship Graschdanin only got hit twice in all of the chaos. at 10:40, Germans ceased fire. The Russians continued to fire on the 3rd M.S.H.F. Around 10:30, Adm. Bachirev ordered all sea forces to withdraw to the northern Suur Strait. The ship Slava was now fatally wounded, destroyed by Turkmerec Strauropolski. The Russians were determined to make the channel impossible to pass through so they laid out more mine and used damaged ships to their advantage. At 10:46, the Werder Battery opened fire on the German battleships. At approximately 11:09, two German battleships anchored while under fire at Võilaid. At 11.28 there was a false submarine alarm followed by a legitimate one at 12:08. Around 1:35, Kolberg attacked Võilaid for approximately ten minutes but met no reply. At 3:45, Adm. Hopman`s flagleutnant Obltz Keln led a landing party to take over Woi. At 5:30, white star shell could be seen which meant that the battery had successfully been taken but the guns were unservicable. By 3:00, Kommodore Heinrich took V100 toward the channel that would lead them to the Suur Strait but were immediately under fire by gunboats under the control of Adm. Makarov. At 10:00pm, Kptlt Zander began to go forward to the Suur Strait. Marker boat S50 took up her position. At the end of the day, German’s were in control over the southern Suur Strait, the Väike Strait and the Matsalu Bay. On the night oc October 17, Russians gave up trying to capture the Suur Strait. Just after midnight on October 18, the S64 was shaken by a mine detonation and was rendered unmanoeuverable. By 1:00 am, it was completely sunk. Come dawn, German torpedo boats took up patrol stations in the Matsalu Bay. The landing operations on Hiiumaa gained momentum between 7:15 and 8:00 am was able to take the area around Emmaste. By 8:30, German minesweepers had worked forward to a mile south of the Viirelaid lighthouse. 766 sank after a mine detonation. At 8:00, Behncke’s group started east and went behind the 3rd M.S.H.F. Just after 10:00, Behncke ordered Adm. Hopman to dispatch Strassburg and the 8th M.S.H.F. to the 3rd squadron while Kolberg, the torpedo boats and Sperrbrecher would remain to the west. At 12:40 the 3rd M.S.H.F. and two boats of the half flotilla confirmed that Slava was sunk along with two freight steamers. The Germans could see Russian destroyers laying mines, the Russians had not yet detected the Germans, so the Germans opened fire, which was met with a reply. Two German torpedo boats opened fire as the Germans continued northward, two Russian gunboats and several destroyers took them under fire. They then turned south at high speed under the cover of a smoke screen. By the evening of the 18th, Kuressaare had been made a supply base, the southern part of Hiiumaa under control of the second Cyclist Battalion and the S-Flotilla landing section, Saaremaa and Muhu were now firmly in German hands. On October 19 the forces of the Gulf of Riga and numerous transport steamers and auxiliaries left the northern Suur Strait under the protection of minesweepers and destroyers. By mid-afternoon, the German forces had penetrated the strait. The German losses were seven minesweepers, nine trawlers and small boats as well as one torpedo boat. The Imperial Navy had a total of 156 dead and 60 wounded. The navy had 54 dead and 141 wounded. The German Army captured 20 130 prisoners, 141 Russian guns including 47 heavy pieces and 130 machine guns. Casualties of the Battle were far more extensive for the Germans than the Russians. 300 German soldiers were killed, and 200 were wounded while the Russians suffered fewer than 100 deaths and around the same number of wounded. German destroyers S-46, S-64 and the Russian destroyer Grom were sunk. All the four ships, Slava, Citizen, König and Kronprinz were damaged but the Slava was in a bad condition. The German battleships Bayern and Grosser Kurfürst were badly damaged, destroyer B-98 was damaged, the A-32 run aground, the auxiliary ship Corsika was damaged, 7 minesweepers and the destroyers S-65 and S-66 were sunk.